==Romanisasi nu teu-baku==
In addition to the standardized systems above, there are many variations in romanization, used either for simplification, in error or confusion between different systems, or for deliberate stylistic reasons.
Notably, the various mappings that [[Japanese input methods]] use to convert keystrokes on a Roman keyboard to kana often combine features of all of the systems; when used as plain text rather than being converted, these are usually known as ''[[wāpuro rōmaji]]''. (''Wāpuro'' is a [[Japanese abbreviated and contracted words| contraction]] of '''''wā'''do '''puro'''sessā'' [word processor].) Unlike the standard systems, wāpuro rōmaji requires no characters from outside the [[ASCII]] character set.
While there may be arguments in favour of some of these variant romanizations in specific contexts, their use, especially if mixed, leads to confusion when romanized Japanese words are indexed.
The following variant romanizations are common: